diff --git a/.gitignore b/.gitignore
index 8e5962e..977d545 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 out
-node_modules
\ No newline at end of file
+node_modules
+elm-stuff
\ No newline at end of file
diff --git a/.vscodeignore b/.vscodeignore
index 795e714..db39920 100644
--- a/.vscodeignore
+++ b/.vscodeignore
@@ -7,3 +7,4 @@ src/**
 .gitignore
 tsconfig.json
 vsc-extension-quickstart.md
+elm-stuff
\ No newline at end of file
diff --git a/examples/Hello.elm b/examples/Hello.elm
index 6cdbaba..8fa683f 100644
--- a/examples/Hello.elm
+++ b/examples/Hello.elm
@@ -1,3 +1,6 @@
-import Html
+import Graphics.Element exposing (..)
+import Graphics.Element exposing (..)
 
-main = Html.text "Hello, World!"
\ No newline at end of file
+main : Element
+main =
+  show "Hello, World!"
diff --git a/examples/elm-package.json b/examples/elm-package.json
new file mode 100644
index 0000000..54765dc
--- /dev/null
+++ b/examples/elm-package.json
@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "summary": "helpful summary of your project, less than 80 characters",
+    "repository": "https://github.com/user/project.git",
+    "license": "BSD3",
+    "source-directories": [
+        "."
+    ],
+    "exposed-modules": [],
+    "dependencies": {
+        "elm-lang/core": "3.0.0 <= v < 4.0.0"
+    },
+    "elm-version": "0.16.0 <= v < 0.17.0"
+}
\ No newline at end of file
diff --git a/src/elmMain.ts b/src/elmMain.ts
index c546958..e939d14 100644
--- a/src/elmMain.ts
+++ b/src/elmMain.ts
@@ -1,24 +1,93 @@
 // The module 'vscode' contains the VS Code extensibility API
 // Import the module and reference it with the alias vscode in your code below
 import * as vscode from 'vscode';
+import cp = require('child_process');
+import path = require('path');
+import os = require('os');
+import fs = require('fs');
+
+export interface ICheckResult {
+	tag: string;
+	overview: string;
+	subregion: string;
+	details: string;
+	region: {
+		start: {
+			line: number;
+			column: number;
+		}
+		end: {
+			line: number;
+			column: number;
+		}
+	}
+	type: string;
+	file: string;
+}
+
+export function checkForErrors(filename): Promise<ICheckResult[]> {
+  return new Promise((resolve, reject) => {
+	var cmd = 'elm-make ' + filename + ' --report=json --output /dev/null'
+	cp.exec(cmd, {}, (err, stdout, stderr) => {
+  	  try {
+		if (err && (<any>err).code == "ENOENT") {
+			vscode.window.showInformationMessage("The 'elm-make' compiler is not available.  Install Elm from http://elm-lang.org/.");
+			return resolve([]);
+		}
+		console.log('stdout', stdout.toString());
+		var lines:ICheckResult[] = JSON.parse(stdout.toString());
+		resolve(lines);
+	  } catch(e) {
+		reject(e);
+	  }
+	});
+
+  });
+}
+
+
+export function createDiagnostics(document: vscode.TextDocument) {
+	if (document.languageId != "elm") {
+		return;
+	}
+	let diagnostics: vscode.Diagnostic[] = [];
+	let compileErrors = vscode.languages.createDiagnosticCollection("compile");
+	let uri = document.uri;
+
+	checkForErrors(uri.fsPath).then((compilerErrors) => {
+		diagnostics = compilerErrors.map((error) => {
+			let lineRange = new vscode.Range(
+				error.region.start.line - 1,
+				error.region.start.column - 1,
+				error.region.end.line - 1,
+				error.region.end.column - 1
+				);
+			return new vscode.Diagnostic(lineRange, error.details.replace(/\[\d+m/g, ''), vscode.DiagnosticSeverity.Error);
+		})
+		compileErrors.set(document.uri, diagnostics);
+		console.log('check success', compilerErrors);
+	}, (error) => {
+		compileErrors.set(document.uri, []);
+		console.log('check error', error)
+	})
+}
 
 // this method is called when your extension is activated
 // your extension is activated the very first time the command is executed
-export function activate(context: vscode.ExtensionContext) {
-
+export function activate(disposables: vscode.Disposable[]) {
 	// Use the console to output diagnostic information (console.log) and errors (console.error)
 	// This line of code will only be executed once when your extension is activated
-	console.log('Congratulations, your extension "elm" is now active!');
+	console.log('Extension "elm" is now active!');
 
-	// The command has been defined in the package.json file
-	// Now provide the implementation of the command with  registerCommand
-	// The commandId parameter must match the command field in package.json
-	var disposable = vscode.commands.registerCommand('extension.sayHello', () => {
-		// The code you place here will be executed every time your command is executed
+//    vscode.workspace.onDidChangeTextDocument(event => {
+//        createDiagnostics(event.document)
+//    }, undefined, disposables);
 
-		// Display a message box to the user
-		vscode.window.showInformationMessage('Hello World!');
-	});
+    vscode.workspace.onDidOpenTextDocument(document => {
+        createDiagnostics(document)
+    });
 
-	context.subscriptions.push(disposable);
+	vscode.workspace.onDidSaveTextDocument(document => {
+		createDiagnostics(document)
+	})
 }
\ No newline at end of file
diff --git a/test/extension.test.ts b/test/extension.test.ts
index 1cec6f4..f20d9d0 100644
--- a/test/extension.test.ts
+++ b/test/extension.test.ts
@@ -1,15 +1,15 @@
-// 
+//
 // Note: This example test is leveraging the Mocha test framework.
 // Please refer to their documentation on https://mochajs.org/ for help.
 //
 
 // The module 'assert' provides assertion methods from node
-import * as assert from 'assert';
+import {assert, test} assert from 'assert';
 
 // You can import and use all API from the 'vscode' module
 // as well as import your extension to test it
 import * as vscode from 'vscode';
-import * as myExtension from '../src/extension';
+import * as elmMain from './../src/elmMain';
 
 // Defines a Mocha test suite to group tests of similar kind together
 suite("Extension Tests", () => {